Thus far, a method that measures a body impedance using electrodes brought into contact with the surface of a body and then calculates a body fat mass using the measured body impedance and a predetermined computation formula has been known as a method for measuring the body fat mass of a person with ease, even in a household.
However, when the measurement subject breathes and his/her trunk area expands/contracts as a result, the positions of his/her internal organs change, and the body impedance value changes as a result. In order to eliminate this influence of breathing, normally, the measurement subject holds his/her breath. However, holding his/her breath places a physical burden on the measurement subject.
Accordingly, JP 2007-268142A (Patent Literature 1), for example, discloses a method that enables the measurement to be carried out without the measurement subject holding his/her breath, or that only requires the measurement subject who hold his/her breath for a short period.
The method disclosed in JP 2007-268142A (Patent Literature 1) measures an impedance multiple times, and when the impedance values measured each time in synchronization with the breathing of the measurement subject in a state where it is determined that the measured impedance value is not erroneous converge, the convergence value is taken as the final value of the impedance for calculating the body fat mass. Meanwhile, although another method disclosed in JP 2007-268142A (Patent Literature 1) requires the measurement subject to hold his/her breath, the method reduces the period for which the breath must be held by issuing a notification prompting the measurement subject to hold his/her breath when the stated convergence has been detected.